Electronics question
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I think so...
If there are no resistance value why d´you want to put it in
a resistance formula??? 
Even though it has a resistance value equal to zero, it still has a resistance value so I thought it would work.
Can someone explain why it doesn't work?
You have to assume the resistance is the limit as it approaches zero.
Feb 2, 2008
0
#6
Lord-Svenstikov wrote:
Even though it has a resistance value equal to zero, it still has a resistance value so I thought it would work.
Can someone explain why it doesn't work?
Because you are using mathematics and dividing by zero is against the rules so your calculator has a heart attack or your mathematics teacher has you flayed alive to discourage others from such heresy.
Of course a super conductor doesn't actually have zero resistance, it just has a very small resistance. Find that small resistance, put it in the formula and you get a big result (but not infinite or a calculator heart attack). The only way you can get zero resistance is by cooling the thing to 0K and you cannot do that due to quantum mucking about.
I suppose we could theoretically achieve a resistance of Zero if we reached Absolute Zero, but I may be wrong.
Feb 2, 2008
0
#8
Unbeliever wrote: I suppose we could theoretically achieve a resistance of Zero if we reached Absolute Zero, but I may be wrong.
Theoretically yes, practically no.
we have nearly acheived that.
If I remember the article in Pop Sci (Popular Science) we are .118 away from absolute zero.
Funny, I'm just watching WLRN and I found out that within the next few days they will be showing something on absolute zero.
I'm glad that it doesn't have a resistance of 0, it is only really close. It makes me feel nice and safe to have the mathematical laws of universe working again.
Thank you for the information people.
Daemon_Panda wrote:
we have nearly acheived that.
If I remember the article in Pop Sci (Popular Science) we are .118 away from absolute zero.
I don't recall reading that. .118 degrees I assume. Celcius or Farenheit?
Feb 3, 2008
0
#13
Alex_M wrote: Daemon_Panda wrote:
we have nearly acheived that.
If I remember the article in Pop Sci (Popular Science) we are .118 away from absolute zero.
I don't recall reading that. .118 degrees I assume. Celcius or Farenheit?
Kelvin. Same scale as Celsius but the Kelvin scale has its zero at absolute zero.
1/Rt = 1/R1+1/R2+...1/Rt
Rt=0=R1...R2....
Rt/1= 1/(1/R1...+1/Rt)
0/1=0 1/(infinite)=0
That 1 in parallel doesn't affect to the infinite.
I know that there are a fair few people on this website who know their physicsy stuff so I would like this out.
Now I know that the formula for adding resistances that are in parrallel is:
1/R(total)=1/R(1)+1/R(2)+1/R(3)...
(Brackets denote subscript)
Now I would like to bring to the topic superconducters which operate with zero resistance. Now logically if you put a path of zero resistance in parrallel with a resistor, of say 1 ohm, then the overall resistance will be zero also.
However the equation breaks down.
1/R(total)=1/1+1/0
Do we just have to asume that the resistance is infinately close to zero?
I wish things would stick to the rules in life.